16. Major Accidents and Disasters

16.1. Introduction

This chapter of the Array Environmental Impact Assessment (EIA) Report presents the assessment of the likely significant effects (LSE1) (as per the EIA Regulations) on the environment of the Ossian Array which is the subject of this application (hereafter referred to as “the Array”) on the vulnerability of the Array to the risks of major accidents and disasters. Specifically, this chapter considers the potential impacts of the Array during the construction, operation and maintenance, and decommissioning phases.
The following technical chapters also inform the assessment presented in this chapter:

a ‘Major Accident’ is an event that threatens immediate or delayed serious environmental effects to human health, welfare and/or the environment and requires the use of resources beyond those that of the client or its appointed representatives (i.e. contractors) to manage. For example, effects that cause a fatality, multiple fatalities or permanent injury, or widespread irreversible harm or damage. Major accidents can be caused by disasters resulting from both man-made and natural hazards;
a ‘Disaster’ is a man-made/external hazard (such as an act of terrorism) or a natural hazard (such as an earthquake) with the potential to cause an event or situation that meets the definition of a major accident as described above; and
a ‘Significant Environmental Effect’ is defined as major accident and/or disaster that could include the loss of life, permanent injury and temporary or permanent destruction of an environmental receptor which cannot be restored through minor clean-up and restoration.

internal project risks: relating to the Array’s potential to cause a major accident and/or disaster; and
external project risks: relating to the vulnerability of the Array to a potential major accident and/or disaster.

These risks have been identified for the Array and have been assessed within this chapter. The chapter identifies the processes and measures which will be implemented to prevent a major accident and/or disaster and to mitigate the significance of effects arising from risks identified. In certain instances, risks identified have been assessed elsewhere within this Array EIA Report, and where this is the case, these assessments are signposted.

The Array EIA Report provides the Scottish Ministers, statutory and non-statutory stakeholders with adequate information to determine the LSE1 of the Array on the receiving environment. This is further outlined in volume 1, chapter 1.
The purpose of this major accidents and disasters Array EIA Report chapter is to:

present the existing environmental baseline established from desktop studies, site-specific surveys and consultation with stakeholders;
identify any assumptions and limitations encountered in compiling the environmental information;
present the LSE1 deriving from the vulnerability of the Array to risks of major accidents and disasters, based on the information gathered and the analysis and assessments undertaken; and
highlight any necessary monitoring and/or mitigation measures which are recommended to prevent, minimise, reduce or offset the likely significant adverse environmental effects of the Array on major accidents and disasters.

The Array will be located off the east coast of Scotland, approximately 80 km south-east of Aberdeen from the nearest point and comprising an area of approximately 859 km2. Further information about the Array and its location are detailed in volume 1, chapter 3. The major accidents and disasters study area (Zone of Influence (ZoI)) for the Array encompasses the potential hazards that may be of relevance to:

the Array (i.e. the area in which the wind turbines, Offshore Substation Platforms (OSPs), inter-array cables and interconnector cables will be located); and
a wider, regional area (north-east Scotland).

Consideration has also been given to the United Kingdom (UK) as a whole to identify any national hazards which may be of relevance to the Array.

Volume 1, chapter 2 of the Array EIA Report presents the policy and legislation of relevance to renewable energy infrastructure. Policy and legislation specifically in relation to major accidents and disasters are as follows, and detailed further in Table 16.1 Open ▸ and Table 16.2 Open ▸ :

The Marine Works (EIA) (Scotland) Regulations 2017 (HM Government, 2017);
Health and Safety at Work etc. Act 1974 (HSWA) and Regulations made Thereunder (HM Government, 1974);
Construction (Design and Management) (CDM) 2015 Regulations (HM Government, 2015a);
Control of Major Accident Hazards (COMAH) Regulations 2015 (HM Government, 2015b);
Scotland’s National Marine Plan (NMP) (Marine Scotland, 2015);
UK Marine Policy Statement (MPS) (HM Government, 2011); and
National Planning Framework (NPF 4) (Scottish Government, 2023a).

Table 16.3 Open ▸ presents a summary of the key issues raised in the Ossian Array Scoping Opinion (Marine Directorate – Licensing and Operations Team (MD-LOT), 2023) along with how these have these have been considered in the development of this major accidents and disasters Array EIA Report chapter. Further detail is presented within volume 1, chapter 5.
To avoid duplication, key issues raised during consultation activities that are relevant to specific topics, such as commercial fisheries, shipping and navigation and aviation, military and communications are included in the relevant EIA Report chapters (volume 2, chapters 12, 13 and 14, respectively).